The 2024 election represented the consolidation of a slow transformation in American party politics. In the mid-20th century, Democratic and Republican support was rooted in a particular combination of class politics and political geography, with Democrats’ emerging strength centered in blue-collar areas, especially in small cities and factory towns across the urban industrial North, and Republicans enjoying far greater success in middle-class suburbs. Over the ensuing 75 years, however, that electoral map has slowly, but inexorably, inverted, thanks to changes in the U.S. economy that have opened the door for cultural politics to drive Americans’ partisanship.
During the administration of Franklin D. Roosevelt, Democrats slowly became the party of the (largely white) working classes, who were the intended beneficiaries of his plethora of New Deal programs. This relationship was cemented by an economy rooted in the industrial production of goods in cities, as well as the passage of the Wagner Act in 1935 — which gave industrial workers the right to organize. This combination meant that American workers became part of an organized, politically coherent working class majority. It also meant that the Democrats’ new voters were geographically concentrated in northern, industrialized cities and towns.
The Democrats remained the dominant party in the U.S. until the 1950s. After the Federal-Aid Highway Act passed in 1956 — which made it possible to commute into the city for work — many middle-class, often ideologically conservative white people abandoned attempts to “defend” city neighborhoods and schools from the Black population, and instead moved to suburbs. This turned the suburbs into Republican strongholds, as issues like busing, school prayer, and sex education mobilized parents into the GOP.
The result was a class-based politics in the U.S. — perhaps for the first time. But from its inception, the relationship between class, geography, and party politics rested on two shaky foundations. First, the disenfranchisement of Black voters in the South before the Voting Rights Act of 1965 suppressed racial politics. Second, cultural issues like abortion had not yet become partisan and many weren't even political. Instead, they remained scarcely discussed private matters. But as liberal social movements emerged and mobilized in the 1960s and 1970s, and conservatives organized their own counter-movement to oppose measures such as the proposed Equal Rights Amendment to the U.S. Constitution, legalized abortion, and more, these two preconditions broke down.
Then, in the 1970s and 1980s, the economic and organizational foundation of America’s class-based politics started to erode. Domestic manufacturing jobs began disappearing as companies increasingly relied on automation or moved production to countries where labor was cheaper. Unions came under sustained attacks from Republicans, as well as employers. The result was that many American workers, particularly those without a college degree, faced a decline in the quality of work available to them: the share of workers receiving “decent” wages (two-thirds of the mean wage for American workers) fell from 61.5% to 55% between 1979 and 2017.